Electrical switch assembly



Oct. 13, 1970 JUNJI OHNO 3,534,196

ELECTRICAL SWITCH ASSEMBLY Filed March 5, 1969 INVENTOR.

JLLALTI 0H #0 BY m HTTOKIVEys United States Patent 3,534,196 ELECTRICALSWITCH ASSEMBLY Junji Ohno, Hamamatsu-shi, Japan, assignor to NipponGakki Seizo Kabushiki Kaisha, Shizuoka-ken, Japan Filed Mar. 3, 1969,Ser'. No. 803,821 Int. Cl. H01h 1/00 US. Cl. 200-166 3 Claims ABSTRACTOF THE DISCLOSURE An electrical switch assembly having movable contactmembers mounted in aligned apertures of spaced plates which can bereadily assembled and disassembled from the switch assembly.

BACKGROUND OF THE INVENTION The present invention relates to anelectrical switch assembly including a movable contact member made ofleaf spring fixed at its base end, a fixed contact member arranged underthe movable contact member near its free end and an actuator fordepressing said movable contact member to move the free end into contactwith said fixed contact member.

The switch assembly of such construction is suitable for a key switch ofan electronic musical instrument.

In the conventional switch assembly heretofore used in the electronicmusical instrument, the movable contact member or members are fixed atits base ends to a switch frame by soldering. Accordingly the assemblingof the movable contact members is troublesome and time-consuming and,after assembled, they cannot be easily disassembled from the switchframe.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide an electrical switch assembly in which a movable contact memberor members can be very easily assembled in the switch assembly by asimple operation.

It is another object of the present invention to provide an electricalswitch assembly in which a movable contact member or any of movablecontact members can be very easily disassembled from the switchassembly.

In accordance with the present invention there is provided an electricalswitch assembly comprising a movable contact member made of leaf springhaving a notched part near its base end, a fixed contact member arrangedunder a free end of the movable contact member, an actuator fordepressing said movable contact member to move the free end into contactwith said fixed contact member, and front and rear supporting platesspaced apart from each other and fixed in the assembly, said supportingplates have aligned apertures for receiving the base portion of themovable contact member, one of said apertures having a recess at theside thereof for receiving said notched part of the movable contactmember to secure its longitudinal position, said front supporting plateurging the movable contact member upward and said rear supporting plateurging the movable contact member downward.

BRIEF DESCRIPTION OF THE DRAWINGS The drawings illustrate a preferredembodiment of the present invention in which;

FIG. 1 schematically shows a key switch for an electronic musicalinstrument embodying the present invention;

FIG. 2 is an exploded perspective view of essential parts of FIG 1; and

FIG. 3 is a similar perspective view showing a modified form.

3,534,196 Patented Oct. 13, 1970 ice FIG. 1 shows a key switch assemblyfor an electronic musical instrument according to the present invention.The switch assembly includes movable contact members 1, fixed contactmembers '2 and an actuator 3. When the actuator 3 is depressed by a keyshown by a broken line 4, it moves the movable contact members 1 intocontact with the corresponding fixed contact members 2.

The key switch according to the present invention, comprises front andrear supporting plates 5 and 5 spaced apart from each other and fixed inthe switch assembly, said supporting plates 5 and 5 having alignedapertures 6 and 6' for receiving the movable contact member 1, saidapertures having recesses 7 and 7' at their one sides, respectively. Themovable contact member 1 has a notched part 8 at its base portion.Counter contact members 9 are arranged above the respective free ends ofthe movable contact members. Each of the movable contact members 1 isinserted through the aligned apertures 6 and 6 of the pair of parallelsupporting plates 5 and 5, and through an opening 10 of the actuator,and the free end of the movable contact member resiliently bears againstthe corresponding counter contact member 9 by its own elasticity.

The movable contact member 1 shown in the drawings has a bent portionand is forcibly passed through the aligned openings 7, 7 and 10, wherebythe front supporting plate 5 urges the movable contact member 1 upwardand the rear supporting plate 5 urges the same downward, thereby biasingthe free end upward.

The notched part 8 of the movable contact member 1 is fitted in therecess 47 at the side of the aperture 6 of the front supporting plate '5whereby the longitudinal position of the member 1 is secured. The sidepart of the movable contact member 1 is supported by the full width ofthe aperture 6 of the rear supporting plate 5'. Thus the movable contactmember is fixedly supported at its base portion by the pair ofsupporting plates 5 and 5'.

Although in the form shown in FIG. 2 the recesses 7 and 7' are formed inthe lower sides of the apertures 6 and 6', respectively, these recessesmay be formed in the upper sides of the apertures 6 and 6. Such amodified form is shown in FIG. 3. In this modified form, the notchedpart 8a of the movable contact member 1a is fitted in a recess 7a formedin one side of an aperture 6a of a rear supporting plate 5a and widepart of the contact member 1a is supported by the full width of anaperture 6a of a front supporting plate 5a.

The a'pertures 6 and 6' have a width slightly wider than that of themovable contact member, and the recesses 7 and 7' have a width slightlywider than that of the notched part 8, while a length of the notchedpart 8 is slightly Wider than the thickness of the front supportingplate, so that the movable contact member snugly fits in the aperture ofthe rear supporting plate and in the recess of the aperture of the frontsupporting plate, whereby the movable contact member is firmly held bythe supporting plates 5 and 5'.

'In the drawings the engagement of the movable contact member 1 with therear supporting plate 5' is made between the wide part of the movablecontact member 1 and the full width of the aperture 6, so that it is notalways necessary to form the recess 7' in the aperture 6' of thesu'pporting plate 5'. By using same shape of the supporting plate 5' asthat of the supporting plate 5 the manufacturing cost can besubstantially reduced.

It will be understood from the above description that according to thepresent invention the movable contact member can be easily assembled inthe electrical switch assembly by inserting the member through thealigned apertures in the pair of parallel supporting plates and theo'pening in the actuator and, after assembled, it can be easilydisassembled from the switch assembly as d esired. This structure can beeasily manufactured by forming notches at the side edges of the movablecontact member made of leaf spring so as to form the narrow parttherein, without requiring any special treatment.

What is claimed is:

1. An electrical switch assembly comprising a movable contact membermade of leaf spring having a notched part near its base end, a fixedcontact member arranged under a free end of the movable contact member,an actuator movably mounted in the assembly for depressing said movablecontact member to move the free end into contact with said fixed contactmember, and front and rear supporting plates spaced apart from eachother and fixed in the assembly, said supporting plates have alignedapertures receiving the base portion of the movable contact member, oneof said apertures having a recess at the side thereof receiving saidnotched part of the movable contact member to secure its longitudinalposition, said front supporting plate urging the movable contact memberupward and said rear supporting plate urging the movable contact memberdownward.

2, An electrical switch assembly according to claim 1, in which therecess is formed at the lower side of the aperture provided in the frontsupporting plate.

3. An electrical switch assembly according to claim 1, in which therecess is formed at the upper side of the aperture provided in the rearsupporting plate.

References Cited UNITED STATES PATENTS 1,857,828 5/1932 Wagar. 2,558,6596/1951 Mock. 2,580,105 12/1951 Krumreich. 2,779,843 1/ 1957 Wiberg. 3,236,987 2/ 1966 Bengtsson.

HERMAN o. JONES, Primary Examiner

